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Watt's Up Applications

  

                                                 

  

                                                                              

  

24

10

WATT'S UP APPLICATIONS

10.1

On Board Use

The Watt's Up is compact and lightweight compared to other Watt meters on the market. 
This allows the Watt's Up to be mounted on board in larger models. This can be convenient
and can also allow the determination of peak Amps, peak Watts and minimum Volts while 
in flight due to the unique features of the Watt's Up. During short test flights, the peak 
Amps peak Watts and minimum Volts generally occur simultaneously under heavy load. 
These values can help give insight into the dynamic performance of the prop or explain 
erratic operation or failures.

10.2

Flight Time

You can calculate flight time at various throttle settings by taking note of the Amps reading
on the Watt's Up and making some simple calculations. Divide the Ah rating of your 
battery pack by the Amps reading to determine the flight time in hours. If your battery pack
is rated in mAh multiply the Amps reading by 1000 to convert it to mAh before dividing.

10.3

Basic Component Selection

You just finished your new model plane and want to select a battery, motor, prop, etc. 
Where do you start? A useful metric for initial component selection is the power to weight 
ratio or power loading. Power loading can be measured in watts/pound. Typical power 
loading ranges from 20 W/lb to 200 W/lb depending on the type of model. Park flyers and 
trainers are on the low end, while acrobatic and 3D models are on the high end.

Select a motor recommended for your model by the manufacture as a starting point. If the 
manufacture does not recommend a motor, select a motor capable of putting out the power 
required for a reasonable power loading for your model. Select a prop that looks suitable 
from the motor manufactures recommendations and the prop manufactures data. Now 
choose a suitable ESC and battery pack of the appropriate voltage.

10.4

Initial Testing

Now that you have chosen components to start with, it’s time to bench test things and do 
some tuning. Keep in mind that a prop performs differently when tested statically on a 
bench compared to dynamically when moving through the air. The faster a prop moves 
through the air, the less thrust it produces. Bench testing can help select well-matched 
components, but should not be taken as the final word. For bench testing, the complete 
system can be assembled on a rolling sled (if you want to make thrust measurements), or 
rigidly mounted. Connect the Watt's Up between the battery pack and the ESC.

Start by taking a baseline measurement at full throttle for comparison. Your battery pack 
should be fully charged for each test. Run the motor up to full throttle and make note of the
Amps, Volts, and Watts readings on the Watt's Up at 30 seconds into the test then turn the 
motor off. Readings at the beginning of the test are not typical due to the initial punch of 
the batter pack, which quickly fades. The Watt's Up captures the peak Amps and peak 
Watts readings which you can compare to the 30 second readings to see how much initial 
punch your pack has.

Divide the Watts reading by the weight of your model to get the power loading. Compare 
this to the desired power loading for your model. Compare the Amps reading to the 
maximum Amps rating of your motor. If it is higher, your motor is being overloaded. If it is
much lower, your motor is larger than you need for the given prop. Now change one of the 
system components such as the prop and run the test again. Continue this procedure until 
you have a well-matched system that provides the desired power loading for your model.

10.5

Balancing Battery Pack Cells

You don't want battery pack cells going below their minimum safe voltages for safety and 
battery life reasons.

"Watt's Up" & "Doc Wattson" Watt Meter and Power Analyzer User's Manual

RC Electronics, Inc.

Содержание Doc Wattson

Страница 1: ...ttson Watt Meter and Power Analyzer User s Manual Model WU100 v2 Please visit our website for the latest version of this manual Visit our website Watt s Up Watt meter www rc electronics usa com Revisi...

Страница 2: ...l other brand and product names mentioned in this manual are trademarks or registered trademarks of their respective owners Changes The material in this manual is for information only and is subject t...

Страница 3: ...CREEN 13 6 2 1 Current Amps A Peak Amps Ap 13 6 2 2 Voltage Volts V Minimum Volts Vm 13 6 2 3 Energy Watt hours Wh 13 6 2 4 Charge Amp hours Ah 13 6 2 5 Power Watts W Peak Watts Wp 14 7 USING WATT S U...

Страница 4: ...SERVO TESTING 25 11 CARE 27 11 1 CLEANING 27 11 2 STORAGE 27 12 TROUBLESHOOTING 28 13 SUPPORT 30 14 WARRANTY 31 14 1 ONE YEAR LIMITED WARRANTY 31 14 2 LIMITS AND EXCLUSIONS 31 14 3 LIMITATION OF LIAB...

Страница 5: ...ir model in ways not possible with the traditional internal combustion engines With Watt s Up it is now easy to determine things like Flight time Current through an ESC and motor ESC BEC and motor eff...

Страница 6: ...controller Made in USA to ISO 9001 2000 quality standards One year warranty and complete user manual 2 2 Specifications Tables Table 1 Electrical Measurement Ranges Parameter Range Resolution Notes Vo...

Страница 7: ...nt rating CAUTION Exceeding these limits may permanently damage the Watt s Up and may cause personal injury and may cause fire 3 2 Electrical Connections and Wiring There are risks associated with the...

Страница 8: ...s responsibility to consider the limitations of any equipment connected to the Watt s Up and not to exceed them since the Watt s Up provides no protection for those components Examples of possible ha...

Страница 9: ...C hobbyists We ll show why later when we discuss current Charge Current Time Charge can be measured in Amp Hours by Amp hours Average Amps hours of duration 4 2 Current Current is measured as an amoun...

Страница 10: ...e applied divided by the amount of resistance Push harder for a given amount of resistance and you get more flow Reducing the diameter of a water pipe increases its resistance and therefore reduces th...

Страница 11: ...d chosen at a particular time depends on the point of view being emphasized by an author Hopefully this will become clear as you read on People often incorrectly mix the concepts of power and energy w...

Страница 12: ...delivered to the prop In battery charging energy from the charger is delivered as a current into a battery where it is converted to a charge stored in the battery s chemistry In a perfect rechargeabl...

Страница 13: ...Loose and intermittent connections can cause component damage 5 2 Using Auxiliary Power By connecting a receiver battery pack of at least 4 0 V or other power source to the 3 pin connector on the SOU...

Страница 14: ...auxiliary 3 pin SOURCE power input connector If you connect an auxiliary power source of 4 0 V or more e g small receiver battery pack the Watt s Up operates independently of power sources on the LOA...

Страница 15: ...s a slight amount of current 7 mA from the SOURCE side Being hundreds of times less current than is drawn by typical loads this slight additional current can be ignored and the SOURCE s current be con...

Страница 16: ...er delivered in Watts over the last screen update interval The displayed Peak Watts value Wp is the maximum power drawn on the LOAD side since the startup screen ended Watts values are measured on the...

Страница 17: ...ng connectors etc have resistance subject to the same resistance based heating The high current handing capabilities of Watt s Up will be maximized when the Watt s Up s SOURCE and LOAD wires are kept...

Страница 18: ...le connections between the Watt s Up and various Sources and Loads using a four wire connection A three wire connection only connects the meter s red plus lead at the LOAD or the SOURCE but not both A...

Страница 19: ...t t s U p w a t t m e t e r B a t t e r y 0 6 0 V D i s c h a r g e L o a d SOURCE LOAD B a t t e r y C h a r g i n g B a t t e r y D i s c h a r g i n g L o a d s P o w e r S o u r c e s L e g e n d...

Страница 20: ...t c h t o r e s e t m e t e r r e a d i n g s b y r e m o v i n g p o w e r c o p y r i g h t 2 0 0 4 2 0 0 7 R C E l e c t r o n i c s I n c A l l r i g h t s r e s e r v e d O p t i o n a l n o r m...

Страница 21: ...transients itself It can be connected through a resistor as well as long as the IR voltage drop from the 7 mA meter operating current results in voltage at the meter that still exceeds the voltage bei...

Страница 22: ...eived as well as the peak Amps Ap and peak Watts Wp used and the minimum voltage on the battery during the charging process Make a note of these final values as they can be used to determine charger e...

Страница 23: ...nce it can be difficult to get manufacturer specifications to match test results it is often simpler and just as useful to record the capacity value of a new battery and save that as a baseline Note t...

Страница 24: ...Watt s Up readings exercise the system by varying things like throttle settings gearbox ratios motor type ESC setup propeller type battery voltage and type drive train type etc Watt s Up allows you to...

Страница 25: ...onents of the system for comparison Start by taking a baseline measurement to compare against Run the prop up to its typical operating RPM using your tachometer and make note of the Watts reading on t...

Страница 26: ...Now choose a suitable ESC and battery pack of the appropriate voltage 10 4 Initial Testing Now that you have chosen components to start with it s time to bench test things and do some tuning Keep in...

Страница 27: ...t the value you calculate from the pack voltage minus a cell or two may be inaccurate to a degree that interferes with your cell balancing We therefore recommend you measure each cell independently Be...

Страница 28: ...exercise your servos simultaneously if possible to create the maximum load on the battery or BEC Monitor the peak Amps peak Watts and minimum Volts to verify acceptable values Unexpected peaks may be...

Страница 29: ...in a cup of lukewarm water Do not apply the detergent directly to your Watt s Up Instead moisten a cloth with the solution and gently wipe your Watt s Up clean CAUTION Do not exert too much pressure o...

Страница 30: ...low voltage Check you have a power source battery or charger supplying at least 4 0 V connected to the SOURCE side wires or to the Auxiliary Power Connector Only have volt readings no Amps Power or o...

Страница 31: ...lue is more than the Peak Amps value the Peak Amps value will match it The Peak Watts value is determined the same way Similarly any time the Volts value is less than the Minimum Volts value the Minim...

Страница 32: ...l Expy 50 194 San Jose CA 95148 Phone 408 705 1980 Fax 408 834 7413 Technical Support Email rc_support rc electronics usa com Customer Service Email rc_customerservice rc electronics usa com Websites...

Страница 33: ...e iv Damage from immersion or cleaning with other than the described procedure v Damaged as a consequence of any repair modification alteration or conversion not performed by RC Electronics Inc This w...

Страница 34: ...our sales invoice Please contact RC Electronics Inc directly to get a RMA and return instructions Carefully pack the Watt s Up and return to the address you are provided The RMA must be clearly labele...

Страница 35: ...Make photocopies so they re always handy Amps Amps Volts Volts Watts Watts Ah Ah Wh Wh Ap Ap Vm Vm Wp Wp Amps Amps Volts Volts Watts Watts Ah Ah Wh Wh Ap Ap Vm Vm Wp Wp Amps Amps Volts Volts Watts Wa...

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